Introduce basic skeleton of the rewritten cachefiles driver including config options so that it can be enabled for compilation. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: linux-cachefs@xxxxxxxxxx Link: https://lore.kernel.org/r/163819622766.215744.9108359326983195047.stgit@xxxxxxxxxxxxxxxxxxxxxx/ # v1 --- fs/Kconfig | 1 fs/Makefile | 1 fs/cachefiles/Kconfig | 21 +++++++ fs/cachefiles/Makefile | 9 +++ fs/cachefiles/internal.h | 115 +++++++++++++++++++++++++++++++++++++ fs/cachefiles/main.c | 53 +++++++++++++++++ include/trace/events/cachefiles.h | 49 ++++++++++++++++ 7 files changed, 249 insertions(+) create mode 100644 fs/cachefiles/Kconfig create mode 100644 fs/cachefiles/Makefile create mode 100644 fs/cachefiles/internal.h create mode 100644 fs/cachefiles/main.c create mode 100644 include/trace/events/cachefiles.h diff --git a/fs/Kconfig b/fs/Kconfig index 86e311377e6e..a6313a969bc5 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -132,6 +132,7 @@ menu "Caches" source "fs/netfs/Kconfig" source "fs/fscache/Kconfig" +source "fs/cachefiles/Kconfig" endmenu diff --git a/fs/Makefile b/fs/Makefile index 290815f3fd31..84c5e4cdfee5 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -125,6 +125,7 @@ obj-$(CONFIG_AFS_FS) += afs/ obj-$(CONFIG_NILFS2_FS) += nilfs2/ obj-$(CONFIG_BEFS_FS) += befs/ obj-$(CONFIG_HOSTFS) += hostfs/ +obj-$(CONFIG_CACHEFILES) += cachefiles/ obj-$(CONFIG_DEBUG_FS) += debugfs/ obj-$(CONFIG_TRACING) += tracefs/ obj-$(CONFIG_OCFS2_FS) += ocfs2/ diff --git a/fs/cachefiles/Kconfig b/fs/cachefiles/Kconfig new file mode 100644 index 000000000000..6827b40f7ddc --- /dev/null +++ b/fs/cachefiles/Kconfig @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config CACHEFILES + tristate "Filesystem caching on files" + depends on FSCACHE && BLOCK + help + This permits use of a mounted filesystem as a cache for other + filesystems - primarily networking filesystems - thus allowing fast + local disk to enhance the speed of slower devices. + + See Documentation/filesystems/caching/cachefiles.rst for more + information. + +config CACHEFILES_DEBUG + bool "Debug CacheFiles" + depends on CACHEFILES + help + This permits debugging to be dynamically enabled in the filesystem + caching on files module. If this is set, the debugging output may be + enabled by setting bits in /sys/modules/cachefiles/parameter/debug or + by including a debugging specifier in /etc/cachefilesd.conf. diff --git a/fs/cachefiles/Makefile b/fs/cachefiles/Makefile new file mode 100644 index 000000000000..a7f3e982e249 --- /dev/null +++ b/fs/cachefiles/Makefile @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for caching in a mounted filesystem +# + +cachefiles-y := \ + main.o + +obj-$(CONFIG_CACHEFILES) := cachefiles.o diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h new file mode 100644 index 000000000000..26e0e23d7702 --- /dev/null +++ b/fs/cachefiles/internal.h @@ -0,0 +1,115 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* General netfs cache on cache files internal defs + * + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@xxxxxxxxxx) + */ + +#ifdef pr_fmt +#undef pr_fmt +#endif + +#define pr_fmt(fmt) "CacheFiles: " fmt + + +#include <linux/fscache-cache.h> +#include <linux/cred.h> +#include <linux/security.h> + + +/* + * Debug tracing. + */ +extern unsigned cachefiles_debug; +#define CACHEFILES_DEBUG_KENTER 1 +#define CACHEFILES_DEBUG_KLEAVE 2 +#define CACHEFILES_DEBUG_KDEBUG 4 + +#define dbgprintk(FMT, ...) \ + printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__) + +#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__) +#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__) +#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__) + + +#if defined(__KDEBUG) +#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__) +#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__) +#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__) + +#elif defined(CONFIG_CACHEFILES_DEBUG) +#define _enter(FMT, ...) \ +do { \ + if (cachefiles_debug & CACHEFILES_DEBUG_KENTER) \ + kenter(FMT, ##__VA_ARGS__); \ +} while (0) + +#define _leave(FMT, ...) \ +do { \ + if (cachefiles_debug & CACHEFILES_DEBUG_KLEAVE) \ + kleave(FMT, ##__VA_ARGS__); \ +} while (0) + +#define _debug(FMT, ...) \ +do { \ + if (cachefiles_debug & CACHEFILES_DEBUG_KDEBUG) \ + kdebug(FMT, ##__VA_ARGS__); \ +} while (0) + +#else +#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__) +#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__) +#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__) +#endif + +#if 1 /* defined(__KDEBUGALL) */ + +#define ASSERT(X) \ +do { \ + if (unlikely(!(X))) { \ + pr_err("\n"); \ + pr_err("Assertion failed\n"); \ + BUG(); \ + } \ +} while (0) + +#define ASSERTCMP(X, OP, Y) \ +do { \ + if (unlikely(!((X) OP (Y)))) { \ + pr_err("\n"); \ + pr_err("Assertion failed\n"); \ + pr_err("%lx " #OP " %lx is false\n", \ + (unsigned long)(X), (unsigned long)(Y)); \ + BUG(); \ + } \ +} while (0) + +#define ASSERTIF(C, X) \ +do { \ + if (unlikely((C) && !(X))) { \ + pr_err("\n"); \ + pr_err("Assertion failed\n"); \ + BUG(); \ + } \ +} while (0) + +#define ASSERTIFCMP(C, X, OP, Y) \ +do { \ + if (unlikely((C) && !((X) OP (Y)))) { \ + pr_err("\n"); \ + pr_err("Assertion failed\n"); \ + pr_err("%lx " #OP " %lx is false\n", \ + (unsigned long)(X), (unsigned long)(Y)); \ + BUG(); \ + } \ +} while (0) + +#else + +#define ASSERT(X) do {} while (0) +#define ASSERTCMP(X, OP, Y) do {} while (0) +#define ASSERTIF(C, X) do {} while (0) +#define ASSERTIFCMP(C, X, OP, Y) do {} while (0) + +#endif diff --git a/fs/cachefiles/main.c b/fs/cachefiles/main.c new file mode 100644 index 000000000000..47bc1cc078de --- /dev/null +++ b/fs/cachefiles/main.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Network filesystem caching backend to use cache files on a premounted + * filesystem + * + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@xxxxxxxxxx) + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/completion.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/namei.h> +#include <linux/mount.h> +#include <linux/statfs.h> +#include <linux/sysctl.h> +#include <linux/miscdevice.h> +#include <linux/netfs.h> +#include <trace/events/netfs.h> +#define CREATE_TRACE_POINTS +#include "internal.h" + +unsigned cachefiles_debug; +module_param_named(debug, cachefiles_debug, uint, S_IWUSR | S_IRUGO); +MODULE_PARM_DESC(cachefiles_debug, "CacheFiles debugging mask"); + +MODULE_DESCRIPTION("Mounted-filesystem based cache"); +MODULE_AUTHOR("Red Hat, Inc."); +MODULE_LICENSE("GPL"); + +/* + * initialise the fs caching module + */ +static int __init cachefiles_init(void) +{ + pr_info("Loaded\n"); + return 0; +} + +fs_initcall(cachefiles_init); + +/* + * clean up on module removal + */ +static void __exit cachefiles_exit(void) +{ + pr_info("Unloading\n"); +} + +module_exit(cachefiles_exit); diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h new file mode 100644 index 000000000000..5ee0aabb20be --- /dev/null +++ b/include/trace/events/cachefiles.h @@ -0,0 +1,49 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* CacheFiles tracepoints + * + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@xxxxxxxxxx) + */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM cachefiles + +#if !defined(_TRACE_CACHEFILES_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_CACHEFILES_H + +#include <linux/tracepoint.h> + +/* + * Define enums for tracing information. + */ +#ifndef __CACHEFILES_DECLARE_TRACE_ENUMS_ONCE_ONLY +#define __CACHEFILES_DECLARE_TRACE_ENUMS_ONCE_ONLY + +#endif + +/* + * Define enum -> string mappings for display. + */ + + +/* + * Export enum symbols via userspace. + */ +#undef EM +#undef E_ +#define EM(a, b) TRACE_DEFINE_ENUM(a); +#define E_(a, b) TRACE_DEFINE_ENUM(a); + +/* + * Now redefine the EM() and E_() macros to map the enums to the strings that + * will be printed in the output. + */ +#undef EM +#undef E_ +#define EM(a, b) { a, b }, +#define E_(a, b) { a, b } + + +#endif /* _TRACE_CACHEFILES_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h>
